Oh man.....I got into a deal like this a few years ago. My son's car was in his name and mine jointly on the title.......but my name was first. He went on a toll road and didn't go through the booth.....went flying through the automatic thing with no funds on his account to pay for it. I received 9 tickets to the tune of about $75 each. Needless to say, I went to court and fought it and the fines were dismissed. I immediately then went to the DOL and had my name removed from the title. That was my eye opener to make sure I had no further legal entanglements with my son.
If you've already taken care of the insurance and license thing, I wouldn't worry about it. But I think sharing your experience (and mine) could be an eye opener for someone else who is still entangled financially with an addict. It can cause a lot of heartache and anxiety.
I hope all works out ok for you.
gentle hugs
ke